Here are a couple of short videos showing two methods to create two-color cast-ons. Both are modifications of the long-tail cast on you may already know.

The first is a simple way to end up with two working yarns after you've cast on your needed stitches. This makes it easy to begin colorwork and takes the use of multiple colors all the way to the start of your project, unifying the look. This cast-on has the same amount of give as a standard long-tail cast-on.

The method in this second video is similar to the first, but this time you will end up with the stitches alternating in color. This cast on gives you a great starting point for working a two-color brioche. Because of the twist added during the cast-on you will have a bit more give than a regular long-tail cast-on, but it's not stretchy, it will only expand as loosely as your cast-on.

I hope you've found this informative and maybe learned a trick or have been inspired to try this out! Happy Knitting!

That's all well and good with a scarf or shawl, but what do you do with a sweater? Here are some tips:

A pieced cardigan
For this you would have (generally) two fronts, two sleeves and a back piece. Each of the fronts is probably close in stitch count to the sleeves so those are easy enough to come pretty close. But your back piece is twice as wide as each front - the simple trick here is to work two balls at a time, alternating one row from each ball. By doing this you are extending the length of the gradient so matching it proportionately with the narrower pieces.

A top-down sweater
This one is also not too hard to solve. If you were being very particular the best bet would be to alternate two balls from the very beginning of the neck cast-on. As you work the yoke and the sweater gets wider, you might want to even bring in a 3rd ball, alternating each ball every round.  When separating the body from the sleeves it might be an idea to work one of the sleeves first (using just one ball) to get a sense of how fast the gradient shifts. You will probably need to dig around in a fresh ball to match up the colors to the yoke. Once the sleeve is done, when you work the body you can judge based on your stitch count and any patterning if you would need 4 or 3 balls for the body if you'd like them to come close to the color shift on the sleeves. Lastly repeat what you did for the first sleeve on the 2nd one. 

Project Tech Specs:
Yarn: Freia Merino Silk Worsted in Canyon and Ecru. This yarn is a little hard to find (your LYS might be able to order it for you), but you can easily sub in our regular wool Ombré Worsted (which is more widely available)

​I hope you've found this useful - ask any questions you might have in the comments below and I'll do my best to answer.